Electric potential has the dimension length squared mass per electric current time cubed.  The SI unit of electric potential is the volt, which is defined as a joule per coulomb.

Another physical quantity with the same dimension is electromotive force.

Maple knows the units of electric potential listed in the following table.

An asterisk ( * ) indicates the default context, an at sign (@) indicates an abbreviation, and under the prefixes column, SI indicates that the unit takes all SI prefixes, IEC indicates that the unit takes IEC prefixes, and SI+ and SI- indicate that the unit takes only positive and negative SI prefixes, respectively.  Refer to a unit in the Units package by indexing the name or symbol with the context, for example, volt[SI] or abV[EMU]; or, if the context is indicated as the default, by using only the unit name or symbol, for example, volt or abV.

The units of electric potential are defined as follows.

An atomic volt is defined as $1$ hartree per electron, approximately $27.21139566$ volts.

An abvolt is defined as $1.\times {10}^{\mathrm{-8}}$ volt and is energy-equivalent to the unit square root dyne centimeter per second ($\frac{\sqrt{\mathrm{dyne}}\mathrm{cm}}{s}$).

A statvolt is defined as $1.\times {10}^{\mathrm{-6}}c$ volts where c is the magnitude of the speed of light, and is energy-equivalent to the unit square root dyne ($\sqrt{\mathrm{dyne}}$).

A planck voltage is defined as a square planck length times planck mass per planck time squared per planck charge.

$\mathrm{convert}\left('\mathrm{volt}'\,'\mathrm{dimensions}'\,'\mathrm{base}'=\mathrm{true}\right)$

$\frac{\mathrm{mass}{\mathrm{length}}^2}{\mathrm{electric\_current}{\mathrm{time}}^3}$

$\mathrm{convert}\left(1.60217733\times {10}^{\mathrm{-19}}\,'\mathrm{units}'\,'V'\,'\mathrm{abV}'\right)$

$1.602177330\times {10}^{\mathrm{-11}}$

$\mathrm{convert}\left(1.60217733\times {10}^{\mathrm{-19}}\,'\mathrm{units}'\,'V'\,\frac{\mathrm{sqrt}\left('\mathrm{dyne}'\right)'\mathrm{cm}'}{'s'}\,'\mathrm{energy}'\right)$

$1.602177330\times {10}^{\mathrm{-11}}$

$\mathrm{convert}\left(1.60217733\times {10}^{\mathrm{-19}}\,'\mathrm{units}'\,'V'\,'\mathrm{statV}'\right)$

$5.344288314\times {10}^{\mathrm{-22}}$

$\mathrm{convert}\left(1.60217733\times {10}^{\mathrm{-19}}\,'\mathrm{units}'\,'V'\,\mathrm{sqrt}\left('\mathrm{dyne}'\right)\,'\mathrm{energy}'\right)$

$5.344288314\times {10}^{\mathrm{-22}}$

$\mathrm{convert}\left(1.60217733\times {10}^{\mathrm{-19}}\,'\mathrm{units}'\,'V'\,'V\left[\mathrm{Atomic}\right]'\right)$

$5.887893132\times {10}^{\mathrm{-21}}$

$\mathrm{convert}\left(1\,'\mathrm{units}'\,'e''V'\,'\mathrm{electronvolt}'\right)$

$1$